mt76: mt7615: enable hw rx-amsdu de-aggregation

Enable hw rx-amsdu de-aggregation support.
This is a preliminary patch to enable rx checksum offload.
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7615/init.c

@@ -116,10 +116,9 @@ mt7615_mac_init(struct mt7615_dev *dev)
 	mt76_set(dev, MT_WF_RMAC_MIB_TIME0, MT_WF_RMAC_MIB_RXTIME_EN);
 	mt76_set(dev, MT_WF_RMAC_MIB_AIRTIME0, MT_WF_RMAC_MIB_RXTIME_EN);
 
-	/* disable hdr translation and hw AMSDU */
 	mt76_wr(dev, MT_DMA_DCR0,
 		FIELD_PREP(MT_DMA_DCR0_MAX_RX_LEN, 3072) |
-		MT_DMA_DCR0_RX_VEC_DROP);
+		MT_DMA_DCR0_RX_VEC_DROP | MT_DMA_DCR0_DAMSDU_EN);
 	/* disable TDLS filtering */
 	mt76_clear(dev, MT_WF_PFCR, MT_WF_PFCR_TDLS_EN);
 	mt76_set(dev, MT_WF_MIB_SCR0, MT_MIB_SCR0_AGG_CNT_RANGE_EN);

drivers/net/wireless/mediatek/mt76/mt7615/mac.c

@@ -238,7 +238,7 @@ static int mt7615_mac_fill_rx(struct mt7615_dev *dev, struct sk_buff *skb)
 	bool unicast, remove_pad, insert_ccmp_hdr = false;
 	int phy_idx;
 	int i, idx;
-	u8 chfreq;
+	u8 chfreq, amsdu_info;
 
 	memset(status, 0, sizeof(*status));
 
@@ -254,6 +254,9 @@ static int mt7615_mac_fill_rx(struct mt7615_dev *dev, struct sk_buff *skb)
 	else
 		phy_idx = -1;
 
+	if (rxd2 & MT_RXD2_NORMAL_AMSDU_ERR)
+		return -EINVAL;
+
 	unicast = (rxd1 & MT_RXD1_NORMAL_ADDR_TYPE) == MT_RXD1_NORMAL_U2M;
 	idx = FIELD_GET(MT_RXD2_NORMAL_WLAN_IDX, rxd2);
 	status->wcid = mt7615_rx_get_wcid(dev, idx, unicast);
@@ -446,6 +449,16 @@ static int mt7615_mac_fill_rx(struct mt7615_dev *dev, struct sk_buff *skb)
 
 	skb_pull(skb, (u8 *)rxd - skb->data + 2 * remove_pad);
 
+	amsdu_info = FIELD_GET(MT_RXD1_NORMAL_PAYLOAD_FORMAT, rxd1);
+	status->amsdu = !!amsdu_info;
+	if (status->amsdu) {
+		status->first_amsdu = amsdu_info == MT_RXD1_FIRST_AMSDU_FRAME;
+		status->last_amsdu = amsdu_info == MT_RXD1_LAST_AMSDU_FRAME;
+		memmove(skb->data + 2, skb->data,
+			ieee80211_get_hdrlen_from_skb(skb));
+		skb_pull(skb, 2);
+	}
+
 	if (insert_ccmp_hdr) {
 		u8 key_id = FIELD_GET(MT_RXD1_NORMAL_KEY_ID, rxd1);
 

drivers/net/wireless/mediatek/mt76/mt7615/mac.h

@@ -33,6 +33,9 @@ enum rx_pkt_type {
 
 #define MT_RXD1_NORMAL_BSSID		GENMASK(31, 26)
 #define MT_RXD1_NORMAL_PAYLOAD_FORMAT	GENMASK(25, 24)
+#define MT_RXD1_FIRST_AMSDU_FRAME	GENMASK(1, 0)
+#define MT_RXD1_MID_AMSDU_FRAME		BIT(1)
+#define MT_RXD1_LAST_AMSDU_FRAME	BIT(0)
 #define MT_RXD1_NORMAL_HDR_TRANS	BIT(23)
 #define MT_RXD1_NORMAL_HDR_OFFSET	BIT(22)
 #define MT_RXD1_NORMAL_MAC_HDR_LEN	GENMASK(21, 16)

drivers/net/wireless/mediatek/mt76/mt7615/regs.h

@@ -368,6 +368,7 @@ enum mt7615_reg_base {
 
 #define MT_DMA_DCR0			MT_WF_DMA(0x000)
 #define MT_DMA_DCR0_MAX_RX_LEN		GENMASK(15, 2)
+#define MT_DMA_DCR0_DAMSDU_EN		BIT(16)
 #define MT_DMA_DCR0_RX_VEC_DROP		BIT(17)
 
 #define MT_DMA_RCFR0(_band)		MT_WF_DMA(0x070 + (_band) * 0x40)